Reproductive behaviour: 1-Sexual behaviour in animalsrhfayed
Reproductive Behaviour involve behaviour patterns associated with courtship, copulation, birth, maternal care and with suckling attempts of newborn. It is species specific behaviour
Fixed Action Pattern (FAP) is a series or sequence of acts that occur behaviorally in animals. it is also known as instinctive behaviour as it is determined by gene of an organism and exhibited automatically without having any prior experience.
Reproductive behaviour: 1-Sexual behaviour in animalsrhfayed
Reproductive Behaviour involve behaviour patterns associated with courtship, copulation, birth, maternal care and with suckling attempts of newborn. It is species specific behaviour
Fixed Action Pattern (FAP) is a series or sequence of acts that occur behaviorally in animals. it is also known as instinctive behaviour as it is determined by gene of an organism and exhibited automatically without having any prior experience.
Social organization and social behaviour in insectsPoojaVishnoi7
Introduction
Properties of a society
Advantages of a society
Disadvantages of a society
Social organisation and social behaviour in insects:-
1. Termites
2.Honeybees
3.Ants
4.Yellow wasp
When a perfectly harmless animal resembles in its colour and shape, with a well protected species, the phenomenon is called mimicry.
The concept of mimicry was first given by H. W. Bates in 1862.
Mimicry is an important feature of organism which protect the animals against enemies. Mimicry often used as self defense which increases the survival value of organisms.
Animal behavior includes all the ways animals interact with other organisms and the physical environment. Behavior can also be defined as a change in the activity of an organism in response to a stimulus, an external or internal cue or combo of cues. ... Behavior is shaped by natural selection.
Two broad categories of behaviors are Proximate and Ultimate behaviour. The presentation gives a brief introduction on Proximate and Ultimate causes of behaviour
Social organization and social behaviour in insectsPoojaVishnoi7
Introduction
Properties of a society
Advantages of a society
Disadvantages of a society
Social organisation and social behaviour in insects:-
1. Termites
2.Honeybees
3.Ants
4.Yellow wasp
When a perfectly harmless animal resembles in its colour and shape, with a well protected species, the phenomenon is called mimicry.
The concept of mimicry was first given by H. W. Bates in 1862.
Mimicry is an important feature of organism which protect the animals against enemies. Mimicry often used as self defense which increases the survival value of organisms.
Animal behavior includes all the ways animals interact with other organisms and the physical environment. Behavior can also be defined as a change in the activity of an organism in response to a stimulus, an external or internal cue or combo of cues. ... Behavior is shaped by natural selection.
Two broad categories of behaviors are Proximate and Ultimate behaviour. The presentation gives a brief introduction on Proximate and Ultimate causes of behaviour
Mutualism describes an interaction that benefits both species. A well-known example exists in the mutualistic relationship between alga and fungus that form lichens. The photosynthesizing alga supplies the fungus with nutrients and gains protection in return. The relationship also allows lichen to colonize habitats inhospitable to either organism alone. In rare cases, mutualistic partners cheat. Some bees and birds receive food rewards without providing pollination services in exchange. These "nectar robbers" chew a hole at the base of the flower and miss contact with the reproductive structures.
Both species involved in the interaction are benefited. These interactions take place in three patterns:
Facultative mutualism – Species survive on their own under favorable conditions
Obligate mutualism – One species is dependent for survival on the other
Diffusive mutualism – One entity can live with multiple partners
These relationships have three purposes:
Defensive mutualism
Trophic mutualism
Dispersive mutualism
Cooperative behavior among members of the same species that includes cooperative nesting, generational overlap, and reproductive division of labor. The termites, the ants, and some of the exceptionally well-organized bees and wasps are among the truly social insects that exhibit eusocial behavior. Multiple effectors such as ecological contributions, kin selection, delayed benefits and multi-level selection drive primitive eusociality towards advanced sociality through a point of "no return". These factors are not mutually exclusive - each may play a different role in the evolution of eusociality in different groups.
What is the evolutionary basis for sexual reproductionSolution.pdfarkleatheray
What is the evolutionary basis for sexual reproduction?
Solution
There are both asexual and sexual reproduction in nearly all groups of animals and plants, in
neither kingdom sex developed as a more rapid means.
When sexual reproduction first originated is still a question. But it is believed that sex originated
in green algae. There are certain species like Ulothrix have different size of spores are
produced. These spores comes in pair and become one and gives valuable new forms. In some
groups of unicellular plants ,the Peridinea, the Conjugatae and the Diatomeae- there is no asexual
reproduction. These are good example of the actual gametic origin.
The whole process of evolution is understand by these lines that first there was a visible
morphological differentiation of gametes, the one becoming a large inactive cell stored with food
, the other becoming small and mobile. Then came the evolution of various sex organs, and
finally the alternation of generation.
There are 3 main categories of sexual life cycles: diploid-dominant, demonstrated by most
animals; haploid - dominant, demonstrated by all fungi and some algae; and the alternation of
generations , demonstrated by plants and some algae.
The Red Queen Hyothesis-
First proposed by Leigh Van Valen in 1973.
According to this hypothesis are species co-evolved with other organisms like predators evolve
with their prey and parasites evolve with their hosts. Each tiny advantages gained by favorable
variations gives a secies an edge over close competitors, predators, parasites, or even prey.
Species that cannot keep up become extinct.
August Weismann proposed an explanation for the evolution of sex, where the advantages of sex
is the creation of variation among siblings.
A similar hypothesis proposed by Charles Darwin in his book Origin of species..
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
1. SYED MUHAMMAD KHAN (BS HONS. ZOOLOGY)
pg. 1
Mating Systems
A mating system is a way in which a group is structured in relation to sexual behavior, i.e.
in animals, the term describes how males and females mate – number of mates, etc.
There are two mating systems:
Monogamy: in this case, an animal has only one mate.
Polygamy: in this case, an animal has more than one mates (it includes polygyny,
polyandry, and polygynandry).
MONOGAMY:
Monogamy is a type of mating system in which an animal has only one mate during their
lifetime or only one mate at any one time. Monogamy is a rare phenomenon in animals.
There are three different types of monogamy:
Sexual monogamy is the practice of having sex only with one mate at a time.
Social monogamy is when animals form pairs to mate and raise offspring but still have
"extra-pair copulations".
Genetic monogamy is used when DNA tests can confirm that a female's offspring are
from only one father.
An estimated 90 percent of all birds are socially monogamous, living, and raising young
together, but many frequently have sex with other partners. One famous experiment
found that female blackbirds paired with sterilized males were still laying eggs that
hatched.
A few animals stay with one mate for life, for example, the mouse-like prairie vole. A male
vole will prefer to mate exclusively with the first female that he mates with. A mated male
vole will even actually attack other females.
2. SYED MUHAMMAD KHAN (BS HONS. ZOOLOGY)
pg. 2
Another example is the black vulture: when extra-pair copulation (other than the one
mate) takes place nearby, vultures will attack that individual. Staying together provides
their babies with biparental care, since both parents incubate eggs, each taking a 24-hour
shift, and for eight months the babies get fed by both parents.
POLYGAMY:
Polygamy is a mating system in which one individual mates with more than one individual
of the opposite sex. It is of three types:
(1) Polygyny:
In polygyny, a single male mates with multiple females. It is the most common mating
system in the animal kingdom. In polygynous systems, the males fight for dominance over
a group of females, and whichever male is the biggest and strongest gets to mate with all
the females. Lions and elephant seals use this type of mating system.
Costs of Polygyny for Males:
In polygynous systems, there is less genetic diversity because one male fathers all of
the offspring.
It increases the chance of inbreeding and the passing on of genetic disorders.
It is difficult for males to handle many females at once.
Costs of Polygyny for Females: Females sometimes encounter infanticide, which is when
a breeding male is overthrown and a new breeding male becomes dominant and kills all
of their current offspring, as he has not fathered them. Because the females no longer
have offspring to nurse, they will go into estrous sooner, which allows the new breeding
male to mate with the females earlier.
3. SYED MUHAMMAD KHAN (BS HONS. ZOOLOGY)
pg. 3
Advantages of Polygyny for Males:
The largest advantage for males in a polygynous mating system is the increased
fitness and reproductive success of the lone male because he will father all the
offspring.
The male also passes on his genes to more individuals.
Advantages of Polygyny for Females:
Some females willingly choose polygyny to gain access to the best resources
available. In these cases, the benefits from superior resource access must outweigh
the opportunity cost of giving up monogamous parental care by a male.
They also can get support from the same group of other females when in danger, like
a female lion.
It is harder for females to find a partner better than their mate in polygyny as compared
to monogamy, unless he is beaten by another male (then that male is considered more
fit).
Female Choice: Female choice, the act in which a female chooses her mate based on
the attractiveness of his qualities, is very common in polygynous systems. In these cases,
females will choose males based on secondary sexual characteristics, which may indicate
access to better and more resources.
(2) Polyandry:
In polyandry, a single female mates with multiple males. It is much rarer as compared to
polygyny. Polyandry has direct benefits for females allowing fertilization assurance,
provision of resources, and parental care for their offspring. House mice (Mus musculus)
have shown indirect, genetic benefits, where females have increased offspring survival
4. SYED MUHAMMAD KHAN (BS HONS. ZOOLOGY)
pg. 4
through multiple mating, showing that practicing polyandry mating results in an increase
in offspring viability (survivability).
(3) Polygynandry:
In polygynandry, multiple males mate with multiple females, it is a combination of
polyandry and polygyny.